Season finale (episode 8) of Invincible was great. I think overall, then, the best episodes of the season were 1, 7, and 8 hands down.
Also by the end of the season, I think the actors got a better sense of how to play their characters and started directing themselves better. I think the voice work is more nuanced, rather than flat as it began.
These last two episodes are brutal and devastating, it was hard sometimes to watch if that can be believed for an animated show. It takes the idea of a bad Superman to its max, far more than we've seen in other properties, and digs into why and how easy it is for someone like that to distance themselves from humanity. It makes "The Boys" look like teddy bear tea time. Invincible just didn't shy away. There were moments where I imagined a really bad visual outcome, then thought they would opt for a nicer route, but no, they took it where I expected it to go. EDIT: I need to stress it was pretty awful, if you have a week stomach. it's exactly what a maniac like Nolan would do to "prove his point" and it is highly effective at proving his point (well, aside from it still not really changing Mark's mind), but damn it is cold and awful and worse than anything on The Boys, which so far is the only equivalent superhero show on TV.
But there's actually some real drama here, on a more adult level. No real clue what's up with Nolan now or where the rest of the series is going.